Inflexion of the snow-and-ice cryogenic energy. How to secure a cool source and preserves it

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2 Preface Residents of snowy, cold regions consume huge amounts of energy such as oil and electricity, and spend a lot of money on personnel expenses to clear snow, considering it to be a headache that prevents social activities during winter. Recently, however, more local governments and private businesses in snowy regions have utilized snow and ice stored in winter as a cold source in summer. Such cold energy is used to air condition public facilities as well as preserve and add value to farm products, which taste better when preserved with snow and ice. Snow and ice cryogenic energy can easily provide inexpensive and stable circulation of low temperature air with high humidity, and is highly valued as an alternative source of energy to oil and clean energy against global warming as it emits no carbon dioxide. It also has many advantages such as preserving freshness, enhancing sugar content, dehumidifying and deodorizing of farm products. Snow and ice cryogenic energy is currently adopted in agricultural facilities, housing complexes (apartments) and welfare facilities. With G8 the Hokkaido Toyako Summit being held this year, cryogenic energy will be used at the press center and New Chitose Airport. It is expected that demand for snow and ice cryogenic energy will further expand into various fields. The enforcement orders of the Act on the Promotion of New Energy Usage (1997) were revised on January 25, 2002, and defined snow and ice cryogenic energy as a new energy. Snow and ice cryogenic energy has been actively promoted since then, and is also attracting attention as a measure against global warming. This book introduces major facilities excerpted from Cool Energy 4, published in Japanese in fiscal We hope it will help people in Japan and overseas to understand the merits of snow and ice cryogenic energy and promote the utilization of this resource. The content of this book will be improved in line with reader feedback and additional information. We appreciate your assistance and cooperation in this. This book was made possible by useful information from Masayoshi Kobiyama, an associate professor of Muroran Institute of Technology, the NPO Association of Snow Utilization Technology and many other related organizations. We would like to express our sincere gratitude to them.

3 Inflexion of the snow-and-ice cryogenic energy Outline Snow and ice are kept until summer as cool source. The cryogenic energy used for the preservation of the harvest by low temperature and the air-conditioning of the public facilities. How to secure a cool source and preserves it! Snow and ice How to secure and preserve snow. a Snow is put in the device that stores snow by using the machine. b Snow packed into the container is carried to the device that stores snow. c Snow is heaped to the snow mound by using the machine in the outdoors. How to secure ice d Water in tanks is frozen by the cold air of winter. e Iceformedinswampsisquarriedandputinanicewarehouse. a Snow is put in the device that stores b Snow packed into the container is snow by using the machine. carried to the device that stores snow. Image : Numata-cho, Hokkaido, snow cool rice factory Image : Sawauchi-mura, Iwate-ken, Yukikko tunnel c Snow is heaped to the snow mound by using the mechine in the outdoors. Snow mound. Image : Cross section of snow dumping site Snow dumping sites (snow mounds)for snow utilization are categorized into the three types of cold air utilization, cold water utilization and snow supply for cryogenic energy, according to the utilization pattern. d The water of the water tank is made to freeze by the cold of winter ice shelter The water of the water tank is made to freeze by the cold of winter. Cold heat of the ice is used for the air-conditioning andtherefrigerationinsummer. The phenomenon that the space where ice coexists with the water is 0 is used Reference Latent Heats Ice shelter make the environment of 0 in both summer and winter. Image : Obihiro-si, Hokkaido, Tsuchiya Dairy Equipment MFG.Co. Monarisk Ice shelter

4 e The ice of the swamp is quarried and put in the ice warehouse Ice forms in the swamp in winter. Ice is cut in the block-shaped. Ice is piled up in the ice warehouse.! Formation of frozen soil using heat pipes This is a method in which water is frozen by transferring the cold energy of winter air into soil, thermal storage tanks and water tanks using heat pipes. The liquid in heat pipes evaporates by taking the heat of the ground. Steam is movedto the top. Then, heat is radiated outside. It is cooled by the air, and it liquefies. It falls down, and cold heat is radiated in the ground. Ground freezes due to these repetitions. In a facility in Omachi, Nagano, water content in water absorbing polymers inside thermal storage tanks is frozen. And, heat isn t moved because summer doesn t liquefy.

5 How to supply cryogenic energy (heat exchange system) How to supply cryogenic energy to the warehouse and the room. a The type which makes cold air circulate and which heat is exchanged for directly. b The type which makes cold water circulate and which heat is exchanged for. c The type that the cold circulates naturally. There are various types which they were combined with. a The type which makes cold air circulateand which heat is exchanged for directly All-air type snow air-conditioner Air is made to circulate between the snow-ice warehouse and storehouse or room by using the ventilator. b The type which makes cold water circulate and which heat is exchanged for Cold-water circulating type snow air-conditioner The water which melted snow or unfreeze liquid on the first side of the device which heat is exchanged for is made to circulate by using the pomp. The liquid on the second sideofthedevice which heat is exchanged for is cooled down. It is often used by the water which has been returned from the device which heat is exchanged for to melt snow. The figure is the example that melted snow is made to circulate on the first side of the device which heat is exchanged for, and air-conditioning by the fan coil unit. c The type that the cold circulates naturally Snow storage shed Yukimuro Himuro A machine isn t used. The cryogenic energy of the snow-ice warehouse or the cryogenic energy of the snow put on the warehouse is made to circulate in the storehouse naturally.

6 Snow warehouses are set up at the Snow Science Museum. Snow meltwater is used for air conditioning of the atrium, conference rooms, library and other rooms in the Lifelong Learning Center. In the Snow Science Museum, farm products are refrigerated by the natural convection of cold energy from a snow warehouse. There is also a long term storage room for grain that includes a special snow storage place where experimentation on long term storage of rice is conducted using the direct heat exchange cold air circulation method. Appearance of the Lifelong Learning Center Appearance of the Snow Science Museum (winter) Address Completion : FY 2001 Facility scale Amount of snow stored : 419 t (Breakdown) Contact : 6 5, 3 chome, Minami 1 jo, Numata cho, Uryu gun : [Lifelong Learning Center] Reinforced concrete structure Two floors above and one floor below ground Total floor area : 2,936 m 2 : Meltwater circulation : 385 t Natural convection : 30 t Cold air circulation : 4 t : Numata Town Board of Education (Tel : ; ext. : 405) When temperatures detected by a thermometry unit at the outlet of the primary side of a heat exchanger do not exceed a preset temperature limit (usually 12 ), water in a thermal storage tank circulates through the heat exchanger. However, when temperatures exceed the preset limit, the water is sent to a snow warehouse and melts snow there. The melted snow water flows into a meltwater tank where it is pumped into the thermal storage tank. When water levels in the thermal storage tank or the meltwater tank reach preset maximum water levels, water is discharged outside to prevent overflowing.

7 Temperatures in three greenhouses for shiitake mushroom growing are controlled using a snow cooling system (summer) and natural cold air (winter). The snow cooling system is comprised of a primary and secondary circuit. In the primary circuit, snow meltwater circulates between an underground snow storage tank and a heat exchanger. In the secondary circuit, coolant water circulates between the heat exchanger and the greenhouses, and cold air is sent into the greenhouses through fan coil units. After all the snow in the snow storage tank has melted, it is refilled with snow from the Numata Method Snow Mound Center. Shitake mushrooms cultivated in the facility are shipped as shitake in the snow. Inside the facility Appearance of the shiitake mushroom growing facility System schematic Address : Aza Hokuryu, Numata cho, Uryu gun Completion : FY 2007 Facility scale : Total floor area : Approx. 275 m 2 (1 greenhouse) x 3 Amount of snow stored : 86 t Contact : Agriculture Promotion Department, Numata Town (Tel : ) Brown rice is stored in the facility using a snow cooled storage system, and the amount of rice stored is the largest in Japan. The facility includes a snow warehouse that contains snow stored in late March (capacity : 3,600 t ), a storage warehouse for brown rice (capacity : 6,000 t ) and a cold air circulatory system that transports cold energy. Air returned from the storage warehouse is sent to the snow warehouse and cooled while passing through multiple tunnels under snow. The chilled air is mixed with returned air in a bypass mixer until both reach a temperature of 4, and the air is sent to the storage warehouse. Appearance Address : Kishichinai, Bibai Completion : FY 2000 Facility scale : Partially two storied steel frame structure Total floor area : Approx. 4,450 m 2 Amount of snow stored : 3,600 t Contact : Bibai City Agricultural Cooperative (Tel : ) Features of the facility 1. One of the largest brown rice cool storage facilities in Japan. 2. Each of four storage rooms can be independently air conditioned. 3. The snow surface cleans air in storage. Bibai s original brand name rice Snow warehouse System chart

8 Asnow cooling system is used for air conditioning in each room of the apartment. The system is comprised of a primary circuit in which cold water circulates through a heat exchanger, and a secondary circuit in which antifreeze liquid containing a preservative circulates. In the primary circuit, cold water from a cold water tank is sent to the heat exchanger, and the returned water is carried to a snow warehouse where it melts snow forcibly in shower form. In the secondary circuit, antifreeze liquid is sent to the fan coil unit of each room before returning to the heat exchanger. During winter, this cooling system is used as a heating system by heating antifreeze liquid with a boiler. Appearance Facility features 1. World s first apartment with a snow cooling system 2. The system is suitable for buildings with many rooms. 3. The system can be used as a clean and safe heating system during winter. Address : Nishi 5 jo, Minami 1 chome, Bibai Completion : FY 1999 Facility scale : Six floors above ground with twenty four units Total floor area : Approx. 1,944 m 2 Air conditioned floor area : Approx. 600 m 2 Amount of snow stored : Approx. 100 t Contact : Nagaoke Co., Ltd. (Tel : ) Appearance Facility features 1. Asnow cooling system is used for changing rooms, the lobby and restaurants and the restaurant in the hot spring facility that has a high heat load. 2. The system cuts electricity expenses by approximately 40% compared with electric air conditioning. Address : 3 ku, Tomei cho, Bibai Putting snow in a snow warehouse Completion : FY 2003 Facility scale : Two storied (partially three storied) reinforced concrete structure Amount of snow stored : 150 t Contact : (Tel : ) Appearance An ice shelter is set up in an underground pit where outside air passes through by means of a passive ventilation system (a natural ventilation system using temperature gaps between the inside and outside of a building) to freeze water in the ice shelter using cold, dry air during winter. During summer, hot and humid outside air is cooled by passing through the ice shelter, and the chilled and dry air is then sent to each room. In addition, snow stored in winter is turned into water by heat exchange to air condition the director s office and other rooms in summer. Address : 3 chome, Midorigaoka Higashi 1 jo, Asahikawa Completion : FY 2002 Facility scale : Partially reinforced concrete steel frame structure Four floors above and one floor below ground Total floor area : 8, 356 m 2 Amount of ice stored : Approx. 100 t Amount of snow stored : Approx. 70 t Contact : Hokkaido Northern Regional Building Research Institute (Tel : )

9 In March, 1,800 tons of snow is piled on the school s grass field and covered with unhulled rice, and stored until summer. The snow is carried into a snow warehouse as needed. In summer, cold air circulates between the snow warehouse and a chicken coop on the school premises, and lowers temperatures in the coop to reduce chickens stress and prevent egg production from decreasing. Appearance (snow warehouse, front ) Address : 1 5, Namiki cho, Iwamizawa Completion : FY 2001 Facility scale : 125 m 2 (chicken coop) Amount of snow stored : 13 t (snow warehouse) Contact : Iwamizawa Agricultural High School (Tel : ) Snow in the park is stored in a warehouse and is used to air condition the entire Glass Pyramid for four months from June to September. The cooling system employs the heat exchange cold water circulation method, but when snow cold energy runs out, a hot and chilled water generator using natural gas (city gas) backs up the system. The system used only snow cold energy to cool the building in summer between fiscal 2005 and 2007, and helped reduce carbon dioxide emissions by around 30 tons per year as an eco friendly air conditioner. Appearance of Glass Pyramid Address : 1 1, Moerenuma Koen, Higashi ku, Sapporo (in Moerenuma Park) Completion : FY 2002 Facility scale : Steel/steel reinforced concrete structure with four floors above ground Total floor area : Approx. 5,329 m 2 (Glass Pyramid) Reinforced concrete structure with one floor below ground Total floor area : Approx. 693 m 2 (snow warehouse) Amount of snow stored : Approx. 3,160 m 2 (approx. 1,580 t) Contact : Glass Pyramid (Tel : ) Entrance of snow warehouse (shutter) State of carrying snow into snow warehouse

10 Appearance Water in ice storage containers in the ice shelter freezes within a month of letting outside winter air into the ice shelter through an inflow port on the lower part of the iceshelter. The environment in the ice shelter is maintained at a temperature of 0 and at a humidity of 100%. Cold energy in the ice shelter is sent to a mixing duct under the office through an underground pipe, and mixed air at a temperature of 12 to 15 is sent out to air condition the office during summer (room temperature : ). Vegetables can be refrigerated in the ice shelter. Monarisk Ice Shelter ice formation schematic Address : 3 2, Nishi 21 jo, Kita 1 chome, Obihiro Completion : FY 1999 Facility outline : Tower type ice shelter (6m in diameter, 5m in height [cylindrical part]) Amount of ice stored : 48 t Air conditioned area of the office : 197 m 2 Contact : Tsuchiya Agricultural Machinery Factory Co. Ltd. (Tel : ) Aheat pipe type practical frozen soil cold warehouse was constructed in Yachiyo cho, Obihiro City in November 2006 based on the results of a demonstration experiment conducted over 20 years in a model plant of Obihiro University of Agriculture and Veterinary Medicine. In this cold warehouse, 60 tons of potatoes (May Queen) are stored and sold. Cold storage increases the sugar content of potatoes by three to four times, which adds to their value. Since the storage period is until the end of June the next year, permafrost is unnecessary. This is why the number of heat pipes can be reduced to 81. State of storage Appearance Address : 176 1, Yachiyo cho Kisen, Obihiro Completion : Nov Facility scale : One story structure with embankment Total floor area of storage : 109 m 2 Number of heat pipes : 81 Contact : Techno Farm Ltd. (Tel : ; Fax : ) Cooperator : Tsuchiya Laboratory, Obihiro University of Agriculture and Veterinary Medicine (Tel : )

11 What is latent heat? Dr. Joseph Black, Glasgow University, England, found the latent heats in 1750s. Generally, when heat is received, temperature of the material rises. And, when heat is radiated, temperature of the material falls down. This is called sensible heats. However, there is a range that a change in temperature isn t caused in the water that temperature is 0 and 100 under the condition of 1 atmospheric pressure, even if it is made to freeze in 0 or it is melted in 0,and even if it is made to evaporate in 100 or it is heated in 100. The heats that spend to phase changes (between the water (liquid)and the ice (solid), and between the water (liquid) and steam (gas)) are called Latent Heats. The Latent Heats when it is spent to phase changes between the water and the ice is about 335kJ/kg (80kcal/kg). And, the Latent Heats when it is spent to phase changes between the water and the steam is about 2500kJ/kg (540kcal/kg). The water contained in the air radiates latent heats in the high sky, and freeze, and it is to snow. Then, snow accumulates on the ground. It can get cold heat by absorbing latent heats in the process that snow changes in the water in warm season. Water becomes ice by radiating latent heats on the ground in the cold season. It can get cold heat by absorbing latent heats in the process that ice changes in the water in warm season. It can get nearby cold energy 0 from the snowand-ice cryogenic energy. When cold air is made to circulate, it can get high humidity, too. It is suitable for the storage of the long period of food through the year, and in the necessary time. This page was written referring to the materials for the Ice shelter society

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